Will a Tesla crash into a wall painted as a road?

On a foggy test track, Mark Rober sat behind the wheel of a Tesla, eyes locked on the road — or at least what the car thought was the road. Moments later, the vehicle slammed straight into a painted illusion of an open street, much like a cartoon character running into a fake tunnel. 

Rober, a former NASA engineer turned YouTube sensation, had just demonstrated a glaring weakness in Tesla's much-touted driver-assistance system.

For years, Tesla has insisted that cameras alone can safely guide its vehicles. The company has removed radar and LIDAR sensors, calling them unnecessary and expensive. Elon Musk himself dismissed LIDAR as "fricking stupid." But Rober's latest experiment suggests otherwise.

In a series of real-world tests, Rober compared a Tesla against a Luminar-equipped Lexus SUV. The results were sobering. When faced with a child-sized mannequin in the middle of the road, the Tesla detected it but failed to stop in time, ploughing through the figure.

Heavy fog and rain further confused the system, rendering its vision unreliable. Meanwhile, the Lexus, aided by LIDAR, stopped precisely every time.

Tesla's approach has long been under scrutiny. Regulators have linked its Autopilot system to multiple crashes, some fatal. Yet Musk continues to push forward, promising an "unsupervised" full self-driving rollout later this year. A robotaxi fleet is also in the works, raising even bigger concerns about safety.